Filter mechanism



Oct. 1 2, 1943. 1 H. LATTA 2,331,332

n FILTER MECHANISM Filed. April lr6, 1942 snventor Patented et., l2, i943 ZBSZ Lynn H. Latta, Deerfield, El., assigner to Agir-Way Electric Appliance Corporation, Toledo, Ohio, a

corporation of Delaware Application April 16, 1942, Serial No. 439,15*?

(Cl.l 18S-73) 9 Claims.

in an imperforate casing in which suctionisapplied to the exterior of the bag so as to draw a dust laden air stream into the bag, a screen being interposed betweenlthe bagv and the casing so as Vto support the bag in spaced relation to the casing wall and permit the air to freely escape from the bag.

The invention has as its general object to provide a dust collecting mechanism of thetype removed without difiiculty. More specifically, vthe invention contemplates an arrangement wherein the bag will, after being partially inserted by hand, slide smoothly into the casing under the pull of the suction unit of thecleaner. f

'Where screens of. conventional type such as woven wire or plain perforated sheet metal are employed, diiculty is experienced in the sticking of the bag to-the screen when suction is applied. This makes it more difficult to'insert the bag. Also,when the bag is fulLthere is a likelihood-dits side wall being torn during re inova-l, against the sharp edges of openings into which it has been extruded during the :iilling process, or by its adherence to the relatively sharp projections of a woven screen. The presentinvention contemplates a screen which provides smooth, rounded surfaces against which the bag :may slide without injury. To this end, I provide a screen in the form of a sleeve of sheet metal, perforated from the inside so that all sharp edges and projections are on the outer side of the screen,` and the perforations are outlined by rounded surfaces curving away from the inner surface of the screen against which the bag maires contact.

Another object of the invention is to provide a specification is considered in connection with the appended drawing, in which:

Fig. 1 is a side elevation of a vacuum'cleaner embodying my invention, portions thereof `being broken away and shown in section;

Fig. 2 is a transverse sectional viewoi the same;

Fig.Y 3 is an enlarged detail longitudinal sectional view of a portion of the' screen; 1 Fig. a is an elevational'view, looking at the inner surface, of va portion of arnodiiied form of the screen; l Fig. 5 is a transverse sectional view taken on the line 5-5 of Figffi; and

Fig'. 6 is an enlarged longitudinal sectional View taken on 'the .linee-5 0i Figli.

Fig. 7 is a transverse A'sectional View of a 'iurther modification oi the invention. i

As an example of one ior'min which the lnl vention may be embodled,"1 have shown in Fig.

indicated, wherein the bag may be inserted and l a vacuum cleaner embodying a base lo housing a suction unit (not shown). On thev base lil is mounted .a tubular-casing i2 oi' the dust collector assembly. vvThe lower end of the casing i2 is secured to a ringl ifi having an inwardly extending `ida-nge i5, the latter being secured to the inturned flange i8 of the base id, withlsuitable vibration absorbingwa-shers 2E interposed therebetween.

At the upper end of the casing i2 is a'mouth framed by a ring 22 sweated or otherwisesutably secured on the casing. VA ring 2d of'com- .pressible material such asrubb'er is mounted in a groove inthe ring i'and forms a seat on which the top ofY the Adust collecting receptacle lA is supported. The mouth of the casing i2 is #closed bya cover 26 lhinged. at 28 to the ring 22 and provided with a latch Sii adapted to co-y act withahook 32 secured to thering E2, `ior latching Athe cover in; closed position. The cover 26 has an annular clamping portion 3Q opposed to the bag seat 24. In the center of the cover is mounted, for swiveling movement, amelbow'.

36 to which a hose may be connected, as by means of a latch 3S. Secured to the underside ofthe cover 26 and communicating with theelbow 36 is a nozzle ill for delivering into the dust collector bag A the dustladen airstream received f through the elbow 3B.

Mounted on the base iis a hose rack i2 in lwhich* the' hose mayl bec'oiled when not' in use.

The dust collectingbag A includes a bag shaped body portion ifi of porous material and an end 'Y member or top i6 `liaving an inlet 48V receiving The topd is dished to provide an `off-set iiange E!! which is received .in the `mouth of thebodyportion lili and secured tliere-v to as by stitching.

The periphery of the top 48 comprises a flange l2 extending outwardly beyond the wall of the body portion 44 and adapted to be clampedbetween the seat 2l and the clamping portion 34 of the cover.

The 'bottom of the bag is adapted to rest against a disc shaped pad 54 of porous material which in turn is supported upon the ange I6 of the ring Il. The nozzle l0 is provided with a gasket 56 of rubber or other suitable compressible material which is adapted to make sealing contact with the upper surface of the top 48.

The present invention provides, in combination with the above described mechanism, a screen B in a form of a sleeve, conforming in general to the contour of the interior of the casing I2, and interposed between the casing I2 and the body portion 44 of the bag A so as to permit free escape from the bag of the air passing therethrough.

Referring now to Fig. 3, the screen B is provided with a plurality of` apertures or perforations I defined by a series of wall portions 60 punched outwardly and presenting to the bags A a series oi' smooth curved surfaces against which the bag will not catch.

A preferable method of perforating the screen is by the use of male die element having a series of pyramidal punch points operating against a female die member having a plurality of round openings adapted to receive the respective points, the result being that the metal in each perforation is split into a plurality of tri-angular shaped projections 82 which are spread apart to form spaces il through which the air passing through the perforations IB may escape into the air passages 68 defined between the screen and the casing wall.

Where the casing I2 is cylindrical, the projections 62 serve to contact the wall of the casing for spacing the screen lin its proper position. Due to inaccuracies in manufacturing, the pro- .lections 62 will be somewhat nonuniform in height and accordingly the contact with the casing wall will be limited to a few of the projection.

In Figs. 4, 5. and 8 I have shown a modified form of the screen in which the apertures 58a are elongated lengthwise of the screen. In forming the apertures 58a. material is removed from the sheet of stock as contrasted to the forming of the screen B in whichthe material is simply split and punched to one side. There are a plurality of annular rows of the apertures 58a, adjacent rows being `separated by webs 66 having outwardly curved side regions as shown.

At the ends of theV apertures 58a the Webs 66 of the screen are pressed outwardly to provide projections 10 which are adapted to contact the wall of the casing for spacing the screen therefrom. l

The apertures 58a may extend either longitudinally or concentrically of the screen.

In the form of the invention shown in Fig. 7 the screen is provided with relatively large apertures 58h. preferably circular in shape, in the form of openings framed by continuous outwardly pressedfianges Elib. The outer edge of each fiange 60h lies in a plane which assumes a chordal relationship to the curved wall of the casing l2 so as to define with the inner surface thereof accurate openings 64b through which the air may escape from the apertures into the space between the screen and the casing.

As shown in Fig. 7, the aperture framing wall portions 60h are frusto-conical, being joined to the body of the screen by curved iillet regions. In a similar manner, the aperture defining wall portions 60 in the form of the invention shown in Fig. 3 and the side extremities of the wall portionsA68 of the form shown in Fig. 4 may be in the form of flat inclined portions joined to the body of the screen by curved fillet regions.

In the operation of the invention, air is drawn through the elbow 36 and nozzle 40 into the bag A. The dust carried by the air is deposited in the bag A while the air passes through the porous Wall Il, then through the apertures 58, then through the spaces 64 into the air passages 66.

In the spaces 66 the air travels downwardly between the screen and the wall I2 until it escapes at the lower end of the screen.

Thence the air passes through an annular space 14 between the filter disc 5I and the casing wall and through a plurality of apertures Il in the flange I6, into the housing ID.

I claim as my invention:

1. In a mechanism for filtering solids from differential pressure impelled streams of gases, a casing, a bag receivable in said casing, and a screen interposed between said bag and said casing, said screen being of sheet metal and having a plurality of apertures outlined by outwardly extended projecting portions of said sheet metal.

2. A filtering mechanism as defined in claim l, wherein said projecting portions are joined to the unperforated inner surface of the screen by convex surfaces merging smoothly with said inner surface.

3. In a mechanism for ltering solids from diiierential pressure impelled streams of gases,

va cylindrical casing, a porous bag receivable in said casing, and a cylindrical screen interposed between said bag and said casing, said screen being formed of sheet metal having a plurality of apertures defined between outwardly extended portions of said sheet metal.

4. In a mechanism for filtering solids from differential pressure impelled streams of gases. an imperforate outer casing having at one end a mouth and including a bag seat encircling said mouth, an 'openable cover for closing said mouth, having a clamping portion cooperable with said bag seat, a dust collecting bag having a body portion of porous material receivable in said casing and having an end member provided with a peripheral portion adapted to be clamped between said seat and said clamping portion, and a screen in the form of a sleeve of sheet metal interposed between said body portion and the wall of the casing, said screen including portions projected outwardly from the main body thereof and defining apertures in the screen, said outwardly projected portions being joined to the body portion of the screen by inclined portions adapted to facilitate sliding of the bag over said apertures.

5. A mechanism for filtering solids from differential pressure impelled streams of gases, comprising a casing, a dust collecting bag of porous paper insertable in said casing, and means for supporting said bag in spaced relationship to the inner surface of said casing, comprising a screen of apertured sheet metal interposed between the bag and the casing, said screen including wall portions extended outwardly to provide rounded aperture framing surfaces adapted to facilitate the sliding of the bag across the apertures.

6. A filtering mechanism as defined in claim 5, wherein said outwardly extended screen por tions are notched to provide spaces for the escape of air from the apertures into the space between the screen and the wall of the casing.

7. A ltering mechanism as dened in claim 5, wherein at least some of said outwardly extending screen portions contactthe wail of the casing to support the screen against the casing and wherein the outwardly extending portions defining each aperture are notched to provide spaces for the escape of air from the aperture into the space between the screen and the casing wall.'

8. A filtering mechanism as dened in claim "5', wherein said apertures are elongated and wherein the screen is provided at the ends of the apertures with protrusions extending radially outwardly vbeyond the extremities oi the sides o! the apertures.

9. A ltering mechanism as defined in claim 5, wherein the aperture framing wall portions are continuous around each aperture, are substantiaily circular in shape, and have their terminal edges disposed chordally with reference to the inner surface of said casing.

. LYNN H. LATTA. 

